Absence of Association between TNF-α Polymorphism and Cerebral Large-Vessel Abnormalities in Adults with Sickle Cell Anemia

Abstract

Stroke is a serious complication of sickle cell anemia (SCA) affecting children and adults. Recent reports suggested that tumor necrosis factor-α (TNF-α) (–308) polymorphism is an important risk factor for stroke in children with SCA. The role of TNF-α polymorphism in the frequency of brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) abnormalities in adults with SCA is still uncertain. Our objective was to evaluate the frequency of TNF-α polymorphism in adults with SCA and to correlate it to brain MRI and MRA findings. TNF-α (–308) polymorphism was determined in 49 adults with SCA. All subjects were evaluated with brain MRI/MRA to establish the presence of intracranial abnormalities. Thirty-three (67.3%) had abnormal brain MRA scans, 8 (16.3%) had intracranial stenosis and 29 (59.2%) showed arterial tortuosity. Forty-one (83.7%) had the GG genotype and 8 had the GA genotype. There was no correlation between homozygosity for G allele and MRA or MRI abnormalities. Although TNF-α (–308) polymorphism is a potential predictor of the genetic risk for stroke in children, we found no association between the polymorphism and large vessel abnormalities in adults with SCA.